FRIDAY, Nov. 16 (HealthDay News) -- While bringing home a live Christmas tree marks the beginning of the holiday season for many, the mold that thrives on its branches can trigger weeks of suffering for some, a new study shows.
Connecticut researchers have found that the mold count from a live Christmas tree rose to five times the normal level two weeks after the tree was brought indoors, and that can prove problematic for people with mold allergies. Their research was presented this week at the American College of Allergy, Asthma & Immunology annual meeting, in Dallas.
"Christmas trees are another possible source of mold exposure during the holiday season," said study co-author Philip Hemmers, an allergist and immunologist with St. Vincent's Medical Center in Bridgeport, Conn. "Mold allergies peak in the fall, and we see a second peak with a lot of our mold-sensitive patients during the holiday season. Our finding correlates with this second peak of mold sensitivity."
The researchers studied the mold growth of a live Christmas tree in a house in Connecticut. Mold reproduce by releasing spores into the air, so after the live Christmas tree was brought inside the house and decorated, the researchers measured mold spore counts. These counts were taken 12 times over a two-week period between Dec. 24 and Jan. 6. The researchers did not assess the types of mold or whether these molds triggered allergic symptoms in people living in the house.
The study found that the mold spore count was 800 spores per square meter (m3) for the first three days. Normal spore counts are less than 1,000 spores/m3, said Hemmers. However, the spore count rose after day four, reaching a maximum of 5,000 spores/m3 by day 14.
"This mold spore count is five times above normal. These high levels have been correlated with allergic rhinitis and an increased rate of asthma symptoms and asthma-related hospitalization in other studies," said Hemmers. "So if you don't feel well during the holidays, consider the Christmas tree as a possible source of allergies."
Hemmers recommended that people with mold sensitivity keep a live Christmas tree in the house for only four to seven days. An artificial tree may be a better option for people with mold allergies, he added, but they carry their own set of problems, especially if they've been stored in the attic or basement where they can collect dust and mold.
Although Christmas trees are not a problem for most people with allergies, said Dr. David Khan, an associate professor of internal medicine at the University of Texas Southwestern Medical Center in Dallas, there are things you can do to minimize their impact.
"If one is mold-allergic, running an air cleaner in the same room as the tree could theoretically reduce the mold exposure, but this has not been studied," he said. "For some people who are sensitive to odors, the aroma from the tree, which most people like, could irritate their nose and cause symptoms. For these people, avoiding live trees may be best."